Air-spring



L. R. GRUSS.

AIR SPRING. APPLICATION FltED FEB.19, I9I6- RENEWED APR. 25. 1918.

1,330,527. Patented Feb. 10,1920. 1'1 .1 F1 .3 I31 .2

Ill 11 U WITNESSES: INVENTOR jzzziz 26 2 2258 v *BWW UNITED sTAtrns PATENT OFFICE.

LUCIEN B. GR'USS, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO PNEUMATIC CUSHION COMPANY, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF CALIFORNIA.

AIR-SPRING.

Specification of Letters Patent.

Patented Feb. 10, 1920.

Application filed February 19, 1916, Serial No. 79,803. Renewed April 25, 1918. Serial No. 280,848.

To all whom it may concern:

Be it' known that I, LUornN R. Games, a

' citizen of the United States, residing in the city and county of San Francisco and State of California, have invented new and useful Improvements in Air-Springs, of which the following is a specification.

This invention relates to vehicle air springs, of the type represented by my former Patent No. 1,142,162, dated June 8, 1915.

The object of the present invention is to provide a simple and eflicient resilient air cushion designed to occupy a minimum amount of space and to operate practically on small quantities of oil.

In carrying out this object, I employ telescoping cylinders forming a closed chamber for compressible fluid, the walls -of said cylinder being spaced 'a slight distance apart; packed joints between the end of each cylinder and the wall of the adjacent cylinder, included in each of which is a cup leather turned downwardly; an oil seal for each of said joints, said cup leathers acting to'autom'atically return the oil to the inner seal which tends to escape between the sliding walls andalso to automatically refill the outer oil seal when the latter runs dry, and means carriedwithin the said cylinders for automatically supplying oil to said inner oil seal. The oil in the interior of the device isrnaintained to a suflicient level so that on the downward movement of th the stand pipe which is fastened to the upper member will dip into the oil overflowing into a trap. Owing to the construction and arrangement of parts this spring will operate successfully within itself with or without an outside shell or sliding jacket. If operated without the jacket it will necessitate the use of a leather boot for dust protection.

One form which my invention may assume is exemplified in the followingedescription and illustrated in the accompanying 'drawing, in which-- Figure 1 shows a vertical'central sectional view of a device embodying my invention.

Fig. 2 shows a similar view of the internal parts in elevation.

Fig. 3 shows a fragmentary section in plan of the spaced cylinder walls,

Fig. 4 shows a sectional view taken on line of Fig. 1.

Fig. 5 shows a. detail of the device in use on a vehicle. Referring in detail to the drawings, the device there illustrated comprises an upper inner cylinder 10 and a lower outer cylinder 11 telescopically connected to form a sin le chamber 12 for compressible fluid. he sliding walls of the two cylinders are spaced a slight distance apart to form an annular space 13 between them, and the inner cylinder carries at its lower end a ring 14 screwthreaded thereon and projecting below and spaced apart from the outer cylinder walls. Arranged between the ring and the outer cylinder Wall is a downwardly turned cup leather 15 expanded outwardly by a convolute spring 16 which together form a tightly packed sliding joint. Below the cup leather 15 is a second cup leather l7 turned upwardly and preferably expanded also bya spring 18 similar to spring 16, said cup leather and ring forming together an inclosed annular space 19 designed to contain oil for sealing the sliding jointwhereby to prevent the escape of air from 'the interior of the device u-pon compression movements of the cylinders.

Carried on the interior of the ring 14 1s an upwardly-extending contracted hollow column 20 forming between it and the walls of the inner cylinder a bucket or trap 21 to contain a quantity of oil which through apertures 22 supplies the oil seal 19.

The bottom of the outer cylinder 11 constitutes a receptacle to contain a quantity of oil which is dipped into upon each compression stroke of the device by the hollow column 20 whereby to maintain said annular trap 21 substantially filled at all times.

At the upper end ofthe outer cylinder 11 is a ring 23 screw-threaded thereon and spaced apart from the walls of the inner cylinder. A downwardly turned cup leather 23, said chamber being adapted to contain oil for sealing the upper sliding jolnt.

In the operation of the device the lower portion of the outer cylinder 1s partlally filled with oil and the trap 21 is also filled.

The upper chamber or seal 27 is supplied' with oil at the beginning of the operation through an inlet 28, communicating preferably with an oil cup not shown. Air is pumped into the chamber 12 through a check valve 29 and the cylinders are extended sufficiently to support the load in normal position. Relative inward movements of the cylinders in operation compress the air in the chamber 12, whereby to cushion the shocks. Oil escaping between the walls of the two cylinders on the compression movements is collected in the space 13 and is returned to the inner seal 19 on the extension movements by the downwardly turned cup leather 2-l wiping the inner cylinder walls. In this manner it is possible to prevent any wastage of oil from the inner oil seal.

The upper and outer oil seal 27 prevents drawing in of air from the outside when the cylinders are compressed, such as would take place on account of the lengthening of the annular space 13, and while a slight vacuum is created on the compression movements of the two cylinders which ma tend to draw oil from the upperseal, this will only be suflicient in quantity to insure proper lubrication of the sliding parts and expansion of the cup leathers. On the other hand, if the oil in the upper seal becomes entirely depleted and the usual supply fails, the upper cup leathers as a consequence become dry and tend to shrink, in which event the oil forced into the annular space 13 will not be returned by the cup leather 24- but will work upwardly and serve to refill the seal 27 and restore the cup leathers to their normal condition. The inner oil seal 19 is kept replenished by the quantity of oil in the trap 21. When the supply in the trap 21 falls below the upper end of the contracted hollow column 20, the well of oil in the lower end of the outer cylinder comes into play to refill said trap when the cylinders are compressed and the said column submerged in the well. By this provision I am enabled to supply at one operation sufficient oil to maintain the device in proper working condition for a maximum length of time without the necessity of carrying too large a quantity of oil adjacent the inner seal which might, on account of its weight, tend to impair the resiliency of the spring.

From the foregoing it will be seen that the sliding joint between the telescoping cylinder 10 fitted with the double set of oppositely turned cup leathers 15.17-2426 in conjunction with the oil seal in trap 21 insures against air leakage from the cylinders and insures return of any oil tending to escape through the sliding j oint.

One particular feature of this device is that it contains the greatest amount of air and the least amount of oil and still makes nected to the inner: cylinder, slidably engaged with the outer cylinder. and also serving to limit the extension movements of the telescoping cylinders, may be provided for dust protection, or a leather boot, not shown, may be substituted for this purpose. Other changes in the arrangement and construction of the various parts may be employed without departing from the spirit of my invention as disclosed in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is 1. An air spring comprising in combination telescoping cylinders forming a chamber for compressible fluid, a packed sliding joint between the end of each cylinder and the wall of the adjacent cylinder, and an oil seal for the inside joint, said joints each having a cup. leather turned downwardly whereby the lower inside cup leather retains the internal pressure in the device on the tion telescoping cylinders forming a cham-.

her for compressible fluid, a packed slidin joint between the end of each cylinder an the wall of the adjacent cylinder, and an oil seal for the inside joint, said joints each having a cup leather turned downwardly whereby the lower inside cup leather retains the internal pressure in the device on the compression and the upper outer leather returns the escaping oil to the inner seal on the extension movements of the device, and an oil seal above the upper outer cup leather.

3. An air spring comprising in combination telescoping cylinders forming a chamber for compressible fluid and havin their adjacent walls spaced a slight dlstance apart, a packed sliding joint between the end of each cylinder and the wall of the adjacent cylinder, and an oil seal for the inside joint, each of said joints havin a on leather turned downwardly where y the lower inside cup leather retains the internal pressure of the device and the upper outer cup leather returns the oil to said seal which tends to escape into the space between the cylinder walls.

4. An air spring comprising in combination telescoping cylinders forming a chamber for compressible fluid and having their the cylinder walls,

adjacent walls spaced a slight distance apart, a packed sliding joint between the end of each cylinder and the wall of the adjacent cylinder, and an oil seal for the inside joint, each of said joints having a cup leather turned downwardly whereby the lower inside cup leather retains the internal pressure of outer cup leather returns the oil to said seal which tends to escape into the space between an upwardly turned cup leather included in said outer sliding joint and an oil seal above said last mentioned cup leather, said parts operating to automatically return the escaping oil to said inner seal. R

5. An air spring comprising in combination telescoping cylinders forming a chamber for compressi le fluid and having their walls spaced a slight distance apart, a packed sliding joint between the end of each cylinder and the Walls of the adjacent cylinder, an oil seal for each of said joints, and an internal source of supply for the inner seal, said joints each having a cup leather arranged in such a manner as to revent the loss of pressure within the device and to automatically return oil escaping .from said inner seal into the spacebetween the cylinders and automatically refill the seal at the outer joint from the source of supply on the interior of the device.

6. An air spring comprising in combination, two upper cylinders secured one within the other, and spaced apart to form an annular chamber, a lower cylinder telescopin into the annular chamber; said upper cy inders and lower cylinder forming two separate chambers for the compression of a compressible fluid, and a member carried by the lower cylinder to support a body of oil around the upper inner cylinder and to direct it thereagainst' to maintain an oil seal between the respective chambers.

7. An air spring comprising in combination, two upper cylinders secured one within the other, and spaced apart to form an annular chamber, a lower cylinder telescoping into the annular chamber; said upper cylinders and lower cylinder forming two the device and. the upper,

'to which said cylinders are separate chambers for the compression of a compressible fluid, and means for maintaining an oil seal in each chamber.

8. An air spring comprising an inner and an outer cylinder, spaced from each other to form an annular chamber, a head member to which said cylinders are secured, a third cylinder adapted to telescope into the annular chamber first named cylinders, a piston member on the upper end of the third cylinder adapted to engage the inner wall of the outermost named cylinder and the outer wall of the innermost cylinder of the first named cylinders; said piston having two cup leathers secured therein, positioned opposite to each other, and a piston on the lower end of the innermost of the first named cylinders engaging the inner wall of the third cylinder..

9. An air spring comprising an inner and an outer cylinder, spaced from each other to form an annular chamber, a head member secured, a third cylinder adapted to telescope into the annular chamber formed between the two first named cylinders, a piston member on the upper end of the third cylinder adapted to engage the inner wall of the outermost named cylinder and the outer wall of the innermost cylinder of the first named cylinders; said iston having two cup leathers secured therein, positioned opposite to each other, a piston on the lower end of the innermost of the first named cylinders engaging the' inner wall of the third cylinder, a pair of compression chambers formed between the respective cylinders, means for maintaining an oil seal above the piston carried by the third cylinder, and means for maintaining an oil seal above the piston carried by the innermost of the first named cylinders.

In testimony whereof I have hereunto set my hand in the-presence of two subscribing witnesses.

Jomw H. Hmmmo, W. W. Hmmr.

formed between the two 

